HCIP-Datacom H12-821_V1.0 Reddit Questions

Explanation of VLAN Pool Assignment Algorithms:

In WLANs, VLAN pools help reduce broadcast domains and improve network performance by distributing users across multiple VLANs. Two algorithms are used for VLAN assignment:

Even Assignment Algorithm:

The number of users in each VLAN is even.

This algorithm assigns users evenly across VLANs, ensuring a balanced distribution of users in each VLAN.

When STAs go offline and online again, their VLANs and IP addresses may easily change.

Since the assignment is based on maintaining even distribution, a device (STA) may not be assigned the same VLAN when it reconnects, leading to potential IP address changes.

Hash Assignment Algorithm:

The number of users in each VLAN is uneven.

The hash algorithm assigns users to VLANs based on a hash value (e.g., derived from the MAC address). This may result in an uneven distribution of users across VLANs.

VLANs and IP addresses remain unchanged for STAs that go offline and online again.

The hash algorithm ensures that a device reconnects to the same VLAN, preserving its IP address.

A screenshot of a computer Description automatically generated

GRE (Generic Routing Encapsulation) is not a Layer 2 VPN technology. Instead, it is a Layer 3 tunneling protocol used to encapsulate a wide variety of network layer protocols inside point-to-point connections. GRE is commonly used for creating VPN tunnels across IP networks, allowing for the transport of various types of payloads. This misunderstanding about GRE being a Layer 2 technology contradicts its definition and typical application ​.

IGMPv3 builds on IGMPv1 and IGMPv2 by supporting all previous query types, including General Query and Group-Specific Query, while introducing Source/Group-Specific Query. This enhancement allows finer control over multicast group membership ​.

LS Ack (Link State Acknowledgment) packets are used to acknowledge received LSAs and do not contain complete LSA information. Instead, they contain only the headers of LSAs being acknowledged. This contrasts with LS Update packets, which carry full LSA details. The misunderstanding of LS Ack functionality makes this statement false ​.